Cartridge, rotary unit, and image forming apparatus

ABSTRACT

A cartridge includes a coupling member, a transmitted member, and a rotary member. The transmitted member includes an accommodating portion configured to accommodate the coupling member, and a protruded portion integrally formed with an inner wall of the accommodating portion and protruding from the inner wall toward an inside of the accommodating portion. The coupling member includes a free end portion having a rotational force receiving portion that receives a rotational force, a connected portion connected to the transmitted member in such a manner that at least a part of the connected portion can be accommodated in the accommodating portion, and a recessed portion provided at the connected portion so that the protruded portion can enter. An inclination angle of a rotation axis of the coupling member relative to a rotation axis of the transmitted member is variable.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an image forming apparatus. Further,the present invention relates to an image forming system.

The image forming apparatus is generally configured to form an image ona recording medium. The image forming apparatus is, for example, anelectrophotographic copying machine, an electrophotographic printer(e.g., a laser beam printer or a light emitting diode (LED) printer), ora facsimile apparatus, which can form an image throughelectrophotographic image forming processes. In general, the imageforming apparatus is associated with a cartridge that is attachable toor detachable from an apparatus body thereof.

Description of the Related Art

There is a conventional developing device the maintenance for which iswholly performed by a service engineer of an office equipment supplierthat has installed an electrophotographic image forming apparatus. Onthe other hand, a cartridge type is employable to enable each user toattach and detach the developing device to and from theelectrophotographic image forming apparatus body. The cartridge type isuseful in that the operability can be improved extremely because a usercan perform the maintenance for the apparatus without relying on anyservice engineer. Therefore, the above-mentioned cartridge type has beenwidely employed for various electrophotographic image formingapparatuses.

The electrophotographic image forming apparatus includes a main bodyside engaging portion provided in the apparatus body to transmit arotational force to a rotary member (e.g., an electrophotographicphotosensitive drum or a developer carrier).

Further, a configuration for causing a coupling member provided on aprocess cartridge to engage with the main body side engaging portion totransmit the rotational force is conventionally known.

The above-mentioned coupling member, which is capable of serving as arotational force transmission unit, can be configured to incline from arotation axis of an electrophotographic photosensitive drum unit.According to such a conventionally known configuration, an engagementoperation or a disengagement operation of the coupling member can berealized in the process of attaching or detaching the process cartridgeto or from the apparatus body. The above-mentioned configurations arediscussed in Japanese Patent No. 4498407, Japanese Patent ApplicationLaid-Open No. 2014-98935, and Japanese Patent Application Laid-Open No.2014-112169.

According to the configuration discussed in Japanese Patent No. 4498407,a coupling member can incline from a drum flange member serving as arotational force transmitted member in a state where these members areconnected to each other. More specifically, the coupling member isconfigured to have a bevel shape and an axial member provided on thedrum flange member is configured to receive the coupling member in sucha way as to enable the coupling member to incline relative to the drumflange member.

Further, according to the configuration discussed in Japanese PatentApplication Laid-Open No. 2014-98935, a coupling member includes aspherical portion that serves as an inclination center. When thespherical portion is assembled with an accommodating portion provided ina drum flange member, the coupling member can be connected to the drumflange member so that the coupling member can incline relative to thedrum flange member.

The spherical portion of the coupling member includes a protrusion thatcan transmit a rotational driving force to the drum flange member. Thedrum flange member includes an aperture having a diameter smaller thanthat of the spherical portion. The spherical portion can be brought intocontact with an inner periphery of the aperture. Thus, it is feasible tohinder the coupling member from separating from the drum flange member.However, according to the above-mentioned configuration, it is necessaryto design the accommodating portion carefully to prevent the innerperiphery of the aperture from colliding with the protrusion of thespherical portion, and to incline the coupling member sufficiently.Therefore, the accommodating portion of the drum flange member tends tobecome greater.

In view of the foregoing, the configuration discussed in Japanese PatentApplication Laid-Open No. 2014-112169 is characterized by causing a pinmember to enter a through-hole of the spherical portion of the couplingmember, instead of using the protrusion having the above-mentionedconfiguration. Further, the pin member is fixed to the drum flangemember in such a way as to enable the coupling member to incline.According to the above-mentioned configuration, the pin member does notcontact with the accommodating portion when the coupling memberinclines, because the pin member is fixed to the drum flange member. Onthe other hand, the total number of parts increases because of the pinmember, which is newly added to the coupling member and the drum flangemember. Further, it is necessary to provide a sufficient clearancebetween the coupling member and the pin member. Therefore, theassembling work is rather complicated because it is necessary to holdboth of the coupling member and the pin member when the coupling memberand the pin member are assembled to the drum flange member.

SUMMARY OF THE INVENTION

The present invention is directed to a technique capable of improvingthe assembling of a cartridge with an image forming apparatus in a casewhere a coupling member is connected to a transmitted member so that thecoupling member can incline relative to the transmitted member.

According to an aspect of the present invention, a cartridge attachableto and detachable from an apparatus body of an image forming apparatus,includes a coupling member configured to receive a rotational force whenthe coupling member engages with a driving member provided on theapparatus body, a transmitted member that includes an accommodatingportion configured to accommodate the coupling member, a protrudedportion integrally formed with an inner wall of the accommodatingportion and protruding from the inner wall toward an inside of theaccommodating portion, and is configured to receive the rotational forcefrom the coupling member, and a rotary member configured to rotate whilecarrying a developer when the rotational force received by thetransmitted member is transmitted to the rotary member. The couplingmember includes a free end portion having a rotational force receivingportion that can be brought into contact with the driving member toreceive the rotational force, a connected portion connected to thetransmitted member in such a manner that at least a part of theconnected portion can be accommodated in the accommodating portion, anda recessed portion provided at the connected portion so that theprotruded portion can enter. An inclination angle of a rotation axis ofthe coupling member relative to a rotation axis of the transmittedmember is variable.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a side view and FIGS. 1B and 1C are cross-sectional views,which illustrate a coupling member assembled with a drive input gear.

FIG. 2 illustrates a cross-sectional side view illustrating anelectrophotographic image forming apparatus.

FIG. 3 is a cross-sectional view illustrating a developing cartridge anda drum cartridge.

FIG. 4 is a perspective view illustrating the developing cartridge,which is seen from a driving side thereof.

FIG. 5 is a perspective view illustrating the developing cartridge,which is seen from a non-driving side thereof.

FIGS. 6A and 6B are exploded perspective views illustrating the drivingside of the developing cartridge.

FIGS. 7A and 7B are exploded perspective views illustrating thenon-driving side of the developing cartridge.

FIGS. 8A to 8D illustrate peripheral components of the coupling member.

FIG. 9 is a side view illustrating a practical configuration of acoupling spring of the developing cartridge.

FIGS. 10A and 10B are perspective views illustrating the drum cartridge.

FIGS. 11A and 11B illustrate the drum cartridge and the developingcartridge in relation to an apparatus body.

FIGS. 12A1 to 12A4 and FIGS. 12B1 to 12B4 illustrate a process ofengaging the coupling member with a main body side driving member whenthe developing cartridge is installed in the apparatus body.

FIGS. 13A and 13B illustrate the coupling member.

FIGS. 14A and 14B are perspective views illustrating the coupling memberengaged with the main body side driving member.

FIG. 15 is a cross-sectional view illustrating the coupling member.

FIG. 16 is a cross-sectional view illustrating the coupling member.

FIGS. 17A and 17B are perspective views illustrating the drive inputgear.

FIG. 18 is a side view illustrating the drive input gear.

FIG. 19 is a cross-sectional view illustrating the drive input gear.

FIGS. 20A and 20B illustrate the coupling member and the drive inputgear, which are separated from each other in a direction parallel toaxial lines L2 and L3, in a state where the axial line L2 substantiallycoincides with the axial line L3.

FIGS. 21A1 to 21A4 and FIGS. 21B1 to 21B4 illustrate a method forassembling the coupling member with the drive input gear.

FIG. 22 is a perspective view illustrating the driving side of thedeveloping cartridge.

FIG. 23 is a cross-sectional view illustrating the driving side of thedeveloping cartridge.

FIG. 24 is a perspective view illustrating the coupling member, thedrive input gear, and a developing side cover, which are separated fromeach other in the direction L3 of the rotation axis of the drive inputgear.

FIG. 25 is a perspective view illustrating the developing side cover andthe developing cartridge in a pre-assembling state.

FIG. 26 is a perspective view illustrating the developing cartridgeincluding the developing side cover.

FIGS. 27A and 27B illustrate the developing cartridge in a state wherethe coupling member is inclined.

FIGS. 28A and 28B are cross-sectional views illustrating the couplingmember, the drive input gear, and the developing side cover, which areassembled with a driving side developing bearing.

FIGS. 29A and 29B are perspective views illustrating the developingcartridge seen from the driving side thereof, in which FIG. 29Aillustrates a coupling member in a driving posture and FIG. 29Billustrates a coupling member in an inclined posture.

FIGS. 30A and 30B illustrate a coupling member of another developingcartridge in an inclined state.

FIGS. 31A and 31B are exploded perspective views illustrating a drivingforce transmission unit, in which FIG. 31A illustrates the driving forcetransmission unit seen from a driving side thereof and FIG. 31Billustrates the driving force transmission unit seen from a non-drivingside thereof.

FIG. 32 is a perspective view illustrating another drum cartridge seenfrom a driving side thereof.

FIG. 33 is a cross-sectional view illustrating the drum cartridge.

FIG. 34A is a perspective view and FIG. 34B is a side view illustratingthe driving side of the drum cartridge.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, the exemplary embodiments for carrying out the presentinvention will be described in detail below with reference to attacheddrawings. However, functions, materials, shapes, and relativepositioning of constituent components described in the followingexemplary embodiments do not intend to limit the scope of the presentinvention narrowly, unless otherwise mentioned. Further, if aconstituent member is once described, initially mentioned material andshape thereof should be referred to in the following description, unlessotherwise mentioned.

Hereinafter, a first exemplary embodiment will be described in detailbelow. A cartridge and an electrophotographic image forming apparatusaccording to the present invention will be described in detail belowwith reference to attached drawings. For example, theelectrophotographic image forming apparatus is constituted by a laserbeam printer. A drum cartridge and a developing cartridge are attachableto and detachable from an apparatus body of the laser beam printer. Inthe following description, the longitudinal directions of the drumcartridge and the developing cartridge are substantially parallel to arotation axis direction L1 of a photosensitive drum and a rotation axisL0 of a developing roller. Further, a rotation axis L10 of thephotosensitive drum and the rotation axis L0 of the developing rollerare intersectional to a recording medium conveyance direction. Further,transverse directions of the drum cartridge and the developing cartridgeare substantially perpendicular to the rotation axis L10 of thephotosensitive drum and the rotation axis L0 of the developing roller.In the present exemplary embodiment, the drum cartridge and thedeveloping cartridge can be attached to and detached from the apparatusbody of the laser beam printer along the transverse directions thereof.Further, reference numerals in the drawings are used to indicateconstituent components and do not intend to narrowly limit theillustrated configuration.

(1) Entire Arrangement of Electrophotographic Image Forming Apparatus

First, an entire configuration of the electrophotographic image formingapparatus according to an exemplary embodiment of the present inventionwill be described in detail below with reference to FIG. 2. FIG. 2illustrates a cross-sectional side view illustrating theelectrophotographic image forming apparatus.

The electrophotographic image forming apparatus illustrated in FIG. 2can form an image on a recording medium 2 with a developer throughelectrophotographic image forming processes based on image informationreceived from an external device (e.g., a personal computer). Further,the electrophotographic image forming apparatus includes a developingcartridge B1 and a drum cartridge C, which can be attached to anddetached from an apparatus body A1 by a user. An example of therecording medium 2 is a recording paper, a label paper, an OHP sheet, ora cloth. Further, the developing cartridge B1 includes a developingroller 13. The drum cartridge C includes a photosensitive drum (i.e., aphotosensitive member) 10 and a charging roller 11.

When a predetermined voltage is applied from the apparatus body A1, thecharging roller 11 uniformly charges a surface of the photosensitivedrum 10. Then, the charged photosensitive drum 10 is irradiated with alaser beam L corresponding to image information received from theoptical unit 1. An electrostatic latent image can be formed on thephotosensitive drum 10 according to the received image information.Then, a developing unit described below develops the electrostaticlatent image with the developer t. Thus, a developer image can be formedon the surface of the photosensitive drum 10.

On the other hand, each recording medium 2 accommodated in a paperfeeding tray 4 can be fed, being separated one by one by a paper feedingroller 3 a and a separation pad 3 b, which is in a pressure contact withthe paper feeding roller 3 a, in synchronization with formation of thedeveloper image. Then, a conveyance guide 3 d conveys the recordingmedium 2 to a transfer roller 6, which serves as a transfer unit. Thetransfer roller 6 is urged toward the surface of the photosensitive drum10 so that transfer roller 6 can constantly contact with thephotosensitive drum 10.

Next, the recording medium 2 passes through a transfer nip portion 6 aformed between the photosensitive drum 10 and the transfer roller 6. Inthis state, a voltage having a polarity opposite to that of thedeveloper image is applied to the transfer roller 6, so that thedeveloper image formed on the surface of the photosensitive drum 10 canbe transferred onto the recording medium 2.

A conveyance guide 3 f conveys the recording medium 2 on which thedeveloper image has been transferred, to a fixing unit 5. The fixingunit 5 includes a driving roller 5 a and a fixing roller 5 c in which aheater 5 b is provided. When the recording medium 2 passes through a nipportion 5 d formed between the driving roller 5 a and the fixing roller5 c, heat and pressure are applied to the recording medium 2 so that thedeveloper image transferred on the recording medium 2 can be fixed tothe recording medium 2. As a result, a visible image can be formed onthe recording medium 2.

Subsequently, the recording medium 2 is conveyed by a discharge rollerpair 3 g and discharged to a discharge portion 3 h.

(2) Electrophotographic Image Forming Processes

Next, the electrophotographic image forming processes according to anexemplary embodiment of the present invention will be described indetail below with reference to FIG. 3. FIG. 3 illustrates a sidecross-sectional view illustrating the developing cartridge B1 and thedrum cartridge C.

As illustrated in FIG. 3, the developing cartridge B1 includes adeveloping container 16, which is associated with the developing roller13 serving as the developing unit and a developing blade 15. Further,the drum cartridge C includes a cleaning frame body 21, in which thephotosensitive drum 10 and the charging roller 11 are provided.

A developer conveyance member 17, which is rotatably supported by thedeveloping container 16, conveys the developer t accommodated in adeveloper storing portion 16 a of the developing container 16 to theinside of the developing chamber 16 c via an aperture 16 b of thedeveloping container 16. The developing roller 13, which contains amagnet roller 12 provided in an inner space thereof, is associated withthe developing container 16. The magnet roller 12 generates a magneticforce that attracts the developer t of the developing chamber 16 a to asurface of the developing roller 13.

Further, the developing blade 15 is constituted by a support member 15a, which is made of a metal plate, and an elastic member 15 b, which ismade of a urethane rubber or a SUS plate. The elastic member 15 b iselastically deformable and generates a predetermined contact pressurewhen the elastic member 15 b contacts the developing roller 13. Thedeveloping roller 13 rotates in a rotational direction X5 to regulatethe amount of the developer t that adheres to the surface of thedeveloping roller 13 and apply frictional electrification charges to thedeveloper t. Thus, a developer layer can be formed on the surface of thedeveloping roller 13. When the developing roller 13 rotates in therotational direction X5 in a state where the voltage is applied from theapparatus body A1, the developer t can be supplied to a developingregion of the photosensitive drum 10.

The charging roller 11, which is rotatably supported by the cleaningframe body 21 and urged appropriately, is in contact with an outercylindrical surface of the photosensitive drum 10. In a state where anappropriate voltage is applied from the apparatus body A1, the chargingroller 11 uniformly charges the surface of the photosensitive drum 10.The voltage to be applied to the charging roller 11 is set beforehand insuch a manner that a potential difference between the surface of thephotosensitive drum 10 and the charging roller 11 becomes equal to orgreater than a discharge start voltage. More specifically, a DC voltageof −1300 V is applied as the charging bias. In this case, the surface ofthe photosensitive drum 10 is uniformly contact-charged to have acharging bias potential (i.e., a dark part potential) of −700V. Further,in the present exemplary embodiment, the charging roller 11 is drivenand rotates around a rotational axis thereof while the photosensitivedrum 10 rotates (as described in detail below). Then, the electrostaticlatent image is formed on the surface of the photosensitive drum 10 withthe laser beam L emitted from the optical unit 1. Then, the developerimage is formed in the developing region of the photosensitive drum 10by transferring the developer t according to the electrostatic latentimage on the photosensitive drum 10 so that the electrostatic latentimage can be visualized.

More specifically, the developing roller 13 is a developer carrier thatrotates in a state where the developer (i.e., toner particles) adheresto a surface thereof (i.e., in a developer carrying state) and developsthe latent image on the photosensitive drum 10 with the developercarried thereon.

Further, the photosensitive drum 10 is an image carrier that carries thedeveloper image formed by the developing roller 13.

The developing roller 13 and the photosensitive drum 10 are rotarymembers that can rotate around their rotational axes in the developercarrying state.

(3) Configuration of Developing Cartridge B1

Next, a practical configuration of the developing cartridge B1 accordingto an exemplary embodiment of the present invention will be described indetail below with reference to the attached drawings. The developingcartridge B1 is a device body of a developing device (i.e., thedeveloping unit) capable of developing a latent image formed on thephotosensitive drum 10, which is configured as a cartridge that can beattached to and detached from the apparatus body of the image formingapparatus.

In the following description, a side in the longitudinal direction atwhich the rotational force can be transmitted from the apparatus body A1to the developing cartridge B1 is referred to as “driving side.” Theopposite side is referred to as “non-driving side.” FIG. 4 is aperspective view illustrating the developing cartridge B1, which is seenfrom a driving side thereof. FIG. 5 is a perspective view illustratingthe developing cartridge B1, which is seen from a non-driving sidethereof. FIG. 6A is an exploded perspective view illustrating thedriving side of the developing cartridge B1, which is seen from aviewpoint positioned outward from the driving side. FIG. 6B is anexploded perspective view illustrating the driving side of thedeveloping cartridge B1, which is seen from a viewpoint positionedinward from the driving side. FIG. 7A is an exploded perspective viewillustrating the non-driving side of the developing cartridge B1, whichis seen from a viewpoint positioned outward from the non-driving side.FIG. 7B is an exploded perspective view illustrating the non-drivingside of the developing cartridge B1, which is seen from a viewpointpositioned inward from the non-driving side. FIG. 1A is a side viewillustrating a coupling member 180 and a drive input gear 27 that areassembled with each other. FIG. 1B is a cross-sectional viewillustrating the coupling member 180 and the drive input gear 27, whichis taken along a cutting plane line S24-S24 illustrated in FIG. 1A. FIG.1C is a cross-sectional view illustrating the coupling member 180 andthe drive input gear 27, which is taken along a cutting plane lineS25-S25 illustrated in FIG. 1A. FIG. 8A illustrates a main body sidedriving member (i.e., a driving member) 100, the developing roller 13, adeveloping roller gear 29, the drive input gear 27, the coupling member180, although other constituent components of the developing cartridgeB1 are not illustrated. FIG. 8A is a perspective view illustrating thevicinity of the coupling member 180. FIG. 8B is an exploded perspectiveview illustrating respective constituent components. Each of FIGS. 8Cand 8D illustrates an engaged state of the coupling member 180 and themain body side driving member 100. FIG. 9 is a side view illustratingthe developing cartridge B1, seen from the driving side thereof.

As illustrated in FIGS. 6A, 6B, 7A, and 7B, the developing cartridge B1includes the developing roller 13 and the developing blade 15. Thedeveloping blade 15 includes a driving side end portion 15 a 1 and anon-driving side end portion 15 a 2 disposed at both ends of the supportmember 15 a in the longitudinal direction and fixed to the developingcontainer 16 with a screw 51 and a screw 52. A driving side developingbearing 36 and a non-driving side developing bearing 46 are disposed atboth ends of the developing container 16 in the longitudinal directionthereof. The developing roller 13 can be rotatably supported when adriving side end portion 13 a is fitted into a hole 36 e of the drivingside developing bearing 36 and a non-driving side end portion 13 c iscoupled with a support portion 46 f of the non-driving side bearing 46.Further, at the driving side end portion 13 a of the developing roller13, the developing roller gear 29 is disposed coaxially with thedeveloping roller 13 and outward from the driving side developingbearing 36 in the longitudinal direction, so that the developing roller13 and the developing roller gear 29 can engage with each other androtate integrally (see FIG. 4).

The driving side developing bearing 36 rotatably supports the driveinput gear 27 at an outer side thereof in the longitudinal direction.The drive input gear 27 is in mesh with the developing roller gear 29.

Further, the coupling member 180 is provided coaxially with the driveinput gear 27.

A developing side cover 34 is provided at a driving side distal endportion of the developing cartridge B1 in such a way as to cover thedrive input gear 27 from the outside in the longitudinal direction.

More specifically, the developing side cover 34 is a cover member thatcovers one end side of the developing cartridge B1 in the longitudinaldirection of the developing roller.

The coupling member 180 protrudes outward via a hole 34 a of thedeveloping side cover 34 in the longitudinal direction. Althoughdescribed in detail below, the coupling member 180 engages with the mainbody side driving member 100 provided on the apparatus body A1 so thatthe rotational force can be transmitted. Further, the rotational forcecan be transmitted to the drive input gear 27 via the connected portion180 b of the coupling member 180. As a result, the rotational forceinput to the coupling member 180 can be transmitted to the developingroller 13 via the drive input gear 27 and the developing roller gear 29.

The coupling member 180 and a peripheral configuration thereof will bedescribed in detail below with reference to the attached drawings.

As illustrated in FIGS. 6A and 6B, the coupling member 180, the driveinput gear 27, and a coupling spring 185 are provided on the drivingside of the developing cartridge B1. The coupling member 180 engageswith the main body side driving member 100 provided on the apparatusbody A1 so that the rotational force can be transmitted to the couplingmember 180. Further, the driving force can be transmitted from thecoupling member 180 to the drive input gear 27 (i.e., a transmittedmember).

More specifically, as illustrated in FIG. 8B, the coupling member 180 ismainly constituted by a free end portion 180 a having rotational forcereceiving portions 180 e 1 and 180 f 1 and the connected portion 180 b.The rotational force receiving portions 180 e 1 and 180 f 1 of thecoupling member 180 are disposed outside a driving side end portion 27 aof the drive input gear 27 in the longitudinal direction. When the mainbody side driving member 100 rotates in a forward rotation direction X6around a rotation axis L1, a rotational force applying portion 100 a 1of the main body side driving member 100 is brought into contact withthe rotational force receiving portion 180 e 1. On the other hand, arotational force applying portion 100 a 2 of the main body side drivingmember 100 is brought into contact with the rotational force receivingportion 180 f 1. Therefore, the rotational force can be transmitted fromthe main body side driving member 100 to the coupling member 180.

The connected portion 180 b of the coupling member 180 is substantiallyspherical. An accommodating portion 27 b on an inner cylindrical surfaceof the drive input gear 27 supports the connected portion 180 b.Although described in detail below, the coupling member 180 is connectedto the drive input gear 27, so that the coupling member 180 can inclinerelative to the drive input gear 27. More specifically, an inclinationangle of the rotation axis of the coupling member 180 relative to therotation axis of the drive input gear 27 is variable.

Further, the connected portion 180 b of the coupling member 180 includesrecessed portions 180 b 2 and 180 b 3 (see FIG. 1) that are provided totransmit the rotational force. The recessed portions 180 b 2 and 180 b 3can contact protruded portions 27 b 2 and 27 b 3 (see FIG. 1) of thedrive input gear 27. Each of the protruded portions 27 b 2 and 27 b 3 isa rotational force transmitted portion. Therefore, the coupling member180 and the drive input gear 27 can be integrated. The drive input gear27 rotates in the forward rotation direction X6 around the rotation axisL3 (as described in detail below).

As illustrated in FIG. 8C, the rotation axis L1 of the main body sidedriving member 100 is set to be coaxial with the rotation axis L3 of thedrive input gear 27. However, due to unevenness in dimensions ofconstituent components, the rotation axis L1 of the main body sidedriving member 100 may slightly deviate from the rotation axis L3 of thedrive input gear 27, as illustrated in FIG. 8D. In such a case, therotational force can be transmitted from the main body side drivingmember 100 to the coupling member 180 while these members are rotatingin a state where the rotation axis L2 of the coupling member 180inclines from the rotation axis L3 of the drive input gear 27. Theposture of the coupling member 180 in the above-mentioned state wherethe coupling member 180 can receive the driving force from the main bodyside driving member 100 is defined as “driving posture.”

Further, as illustrated in FIG. 8A, the drive input gear 27 includes anintegrally formed gear portion (i.e., a first gear) 27 c, which is ahelical gear or a spur gear. The gear portion 27 c is coaxial with therotation axis L3 of the drive input gear 27. The gear portion 27 c isprovided on an outer cylindrical surface of the drive input gear 27 (theaccommodating portion 27 b).

Further, the gear portion 27 c meshes with a gear portion 29 a of thedeveloping roller gear 29. The developing roller gear 29 and thedeveloping roller 13 rotate integrally. Therefore, the rotational forceof the drive input gear 27 can be transmitted to the developing roller13 via the developing roller gear 29. Further, the developing roller 13rotates in the rotational direction X5 around the rotation axis L0.

Further, as illustrated in FIGS. 6 and 9, the coupling spring 185 isprovided on the developing side cover 34. The coupling spring 185 is,for example, a torsion coil spring. A positioning portion 185 a of thecoupling spring 185 is supported by a spring accommodating portion 34 hof the developing side cover 34. Further, one end portion 185 b of thecoupling spring 185 is fixed to a spring engaging portion 34 j of thedeveloping side cover 34. Further, under a restorative force of thecoupling spring 185, the other end portion 185 c of the coupling spring185 is in contact with a linking portion 180 c of the coupling member180 in such a way as to inline the rotation axis L2 of the couplingmember 180 from the rotation axis L3 of the drive input gear 27.

When an inclination regulating portion 180 b 4 provided on the rotationaxis of the coupling member 180 collides with a regulating portion 36 b1 of a regulating accommodating portion 36 a of the driving sidedeveloping bearing 36, the coupling member 180 can be held in aninclined posture, as described in detail below. The posture of thecoupling member 180 in the above-mentioned inclined state is defined as“inclined posture.”

(4) Schematic Configuration of Drum Cartridge C

Next, a practical configuration of the drum cartridge C will bedescribed in detail below with reference to FIGS. 10A and 10B. FIG. 10Ais a perspective view illustrating the drum cartridge C, which is seenfrom a non-driving side thereof. FIG. 10B is a perspective viewillustrating the photosensitive drum 10 and the charging roller 11, andperipheral components thereof, in a state where the cleaning frame body21, a drum bearing 30, and a drum shaft 54 are removed.

The drum cartridge C includes the photosensitive drum 10 and thecharging roller 11, as illustrated in FIGS. 10A and 10B. The chargingroller 11 is rotatably supported by a charging roller bearing 67 a and acharging roller bearing 67 b and is urged against the photosensitivedrum 10 by a charging roller urging member 68 a and a charging rollerurging member 68 b.

A driving side flange 24 is integrally fixed to a driving side endportion 10 a of the photosensitive drum 10. A non-driving side flange 28is integrally fixed to a non-driving side end portion 10 b of thephotosensitive drum 10. The driving side flange 24 and the non-drivingside flange 28 are fixed to the photosensitive drum 10, by means ofcalking or bonding, and are coaxially with the photosensitive drum 10.The drum bearing 30 is fixed to the driving side end portion 10 a andthe drum shaft 54 is fixed to the non-driving side end portion 10 b, bymeans of screws, bonding, or press fitting, at both end portions of thecleaning frame body 21 in the longitudinal direction. The driving sideflange 24 integrally fixed to the photosensitive drum 10 is rotatablysupported by the drum bearing 30. Further, the non-driving side flange28 is rotatably supported by the drum shaft 54.

Further, a charging roller gear 69 is provided at one end of thecharging roller 11 in the longitudinal direction. The charging rollergear 69 is in mesh with a gear portion 24 c of the driving side flange24. Although not illustrated, the rotational force can be transmittedfrom the apparatus body A1 to a driving side end portion 24 a of thedrum flange 24. As a result, when the photosensitive drum 10 is drivento rotate around a rotational axis thereof, the charging roller 11 isdriven to rotate around the rotational axis thereof. As mentioned above,the circumferential speed of the surface of the charging roller 11 isset to be approximately 105% to 120% of the circumferential speed of thesurface of the photosensitive drum 10.

(Installation of Developing Cartridge B1 and Drum Cartridge C to MainBody Apparatus A1)

Next, a method for installing the developing cartridge B1 and the drumcartridge C to the apparatus body A1 will be described in detail belowwith reference to FIGS. 11A and 11B, which illustrate a process ofattaching and detaching the developing cartridge B1 and the drumcartridge C to and from the apparatus body A1. FIG. 11A is a perspectiveview illustrating the developing cartridge B1 and the drum cartridge C,which are seen from the non-driving side thereof. FIG. 11B is aperspective view illustrating the developing cartridge B1 and the drumcartridge C, which are seen from the driving side thereof.

As illustrated in FIGS. 11A and 11B, the apparatus body A1 can be openedby rotating a main body cover 94 disposed at an upper part of theapparatus body A1 in an opening direction D1.

Subsequently, a guided portion 46 d (see FIG. 11A) of the non-drivingside bearing 46 of the developing cartridge B1 is engaged with a firstguide portion 93 a (see FIG. 11B) of the non-driving side guide member93 of the apparatus body A1. Then, a guided portion 34 d (see FIG. 11B)of the developing side cover 34 of the developing cartridge B1 isengaged with a first guide portion 92 a of the driving side guide member92 (see FIG. 11A) of the apparatus body A1. Thus, the developingcartridge B1 is inserted into the apparatus body A1 alongattachment/detachment paths X1 and XH1 formed by the first guide portion92 a of the driving side guide member 92 and the first guide portion 93a of the non-driving side guide member 93.

Similarly, a non-driving side guide portion 21 a (see FIG. 11A) of thecleaning frame body 21 of the drum cartridge C is engaged with a secondguide portion 93 b (see FIG. 11B) of the non-driving side guide member93 of the apparatus body A1. Then, a driving side guide portion 24 g(see FIG. 11B) of the driving side flange 24 of the drum cartridge C isengaged with a second guide portion 92 b (see FIG. 11A) of the drivingside guide member 92 of the apparatus body A1. Thus, the drum cartridgeC is inserted into the apparatus body A1 along attachment/detachmentpaths X2 and XH2 formed by the second guide portion 92 b of the drivingside guide member 92 and the second guide portion 93 b of thenon-driving side guide member 93.

An operation for installing the cartridge B1 on the apparatus body A1,accompanied by inclination (or tilt) of the coupling member 180, will bedescribed in detail below with reference to FIG. 12.

FIG. 12 illustrates a process of attaching and detaching the developingcartridge B1 to and from the apparatus body A1, while causing thecoupling member 180 to incline (or tilt). FIGS. 12A1 to 12A4 areenlarged views respectively illustrating the vicinity of the couplingmember 180, which are seen from the driving side thereof. FIGS. 12B1 to12B4 are schematic views of FIG. 12A1 to 12A4, which are seen from alower surface perpendicular to a direction indicated by an arrow X1. Theinstallation operation progresses successively as illustrated in FIGS.12A1 through 12A4. FIG. 12A4 illustrates an installation completionstate. In FIG. 12, the driving side guide member 92 and the main bodyside driving member 100 belong to the apparatus body A1. Otherconstituent components belong to the developing cartridge B1.

As illustrated in FIGS. 12A1, 12B1, 12A2, and 12B2, the installationoperation includes inserting the developing cartridge B1 into theapparatus body A1 in the direction X1 along the driving side guidemember 92. The direction X1 is a predetermined direction substantiallyperpendicular to the rotation axis L1 of the main body side drivingmember 100.

In this case, the coupling member 180 is held in a state where the freeend portion 180 a is directed in a direction approaching the main bodyside driving member 100, by the coupling spring 185, which serving as anurging member (i.e., an elastic member), provided on the developingcartridge B1. While keeping this state, the developing cartridge B1 isinserted into the apparatus body A1. In the present exemplaryembodiment, the axial line L3 represents the rotation axis of the driveinput gear 27, the axial line L2 represents the rotation axis of thecoupling member 180, and the axial line L1 represents the rotation axisof the main body side driving member 100. In the above-mentioned state,the axial line L2 is inclined relative to the axial line L3 and theaxial line L1.

If the developing cartridge B1 is further inserted in the direction X1,the coupling member 180 is brought into contact with the main body sidedriving member 100, as illustrated in FIGS. 12A3 and 12B3. According tothe illustrated example, a flat surface portion 180 a 1 provided at thefree end portion 180 a of the coupling member 180 is in contact with therotational force applying portion 100 a 1 of the main body side drivingmember 100. The above-mentioned contact state regulates the position ofthe coupling member 180. The inclination (tilt) amount of the axial lineL2 relative to the axial line L1 (or the axial line L3) graduallydecreases.

When the developing cartridge B1 is fully inserted until it reaches aninstallation completion position, the axial line L2 and the axial lineL1 (the axial line L3) are positioned on substantially the same straightline, as illustrated in FIGS. 12A4 and 12B4.

When the coupling member 180 is engaged with the main body side drivingmember 100 as mentioned above, transmitting the rotational force becomesfeasible.

When the developing cartridge B1 is removed from the apparatus body A1,the removal operation progresses oppositely from the states illustratedin FIGS. 12A4 and 12B4 to the states illustrated in FIGS. 12A1 and 12B1.When the coupling member 180 inclines (tilts) from the axial line L3,the coupling member 180 can be disengaged from the main body sidedriving member 100. More specifically, when the developing cartridge B1moves in a direction X3 that is opposite to the direction X1, thecoupling member 180 can be disengaged from the main body side drivingmember 100. The direction X3 is a predetermined direction substantiallyperpendicular to the rotation axis L1 of the main body side drivingmember 100.

In the present exemplary embodiment, the coupling spring 185 causes thefree end portion 180 a of the coupling member 180 to face the directionapproaching the main body side driving member 100 when the developingcartridge B1 is installed to or removed from the main body A1. Althoughit depends on a relationship between the installation direction X1 andthe gravity direction or the weight of the coupling member 180, it maybe feasible to cause the free end portion 180 a of the coupling member180 to face the direction X1 without relying on the coupling spring 185.In this case, the coupling spring 185 is unnecessary.

It is required that the developing cartridge B1 moves in the directionX1 or the direction X3 only when the developing cartridge B1 is in thevicinity of the installation completion position. In other words, thedeveloping cartridge B1 can move in any direction if the developingcartridge B1 is far from the installation completion position. In short,it is required to move in the predetermined direction substantiallyperpendicular to the rotation axis L1 of the main body side drivingmember 100 only at engagement completion or disengagement start timingof the coupling member 180.

(Configuration of Coupling Member)

The coupling member 180 will be described in detail below with referenceto the attached drawings.

FIGS. 13A and 13B illustrate the coupling member 180. FIG. 13A is a sideview illustrating the coupling member 180. FIG. 13B illustrates thecoupling member 180 seen from a direction V2 illustrated in FIG. 13A.FIGS. 14A and 14B are perspective views illustrating the coupling member180 engaged with the main body side driving member 100. FIG. 14A is aperspective view illustrating the engaged state seen from a viewpointpositioned adjacent to the main body side driving member 100. FIG. 14Bis a perspective view illustrating the engaged state seen from aviewpoint positioned adjacent to the coupling member 180. FIG. 15 is across-sectional view illustrating the coupling member 180, which istaken along a cutting plane line S1-S1 that includes the axial line L2illustrated in FIG. 13A. Further, a hatching portion represents a crosssection in not only FIG. 15 but also in other cross-sectional views.FIG. 16 is a cross-sectional view illustrating the coupling member 180,which is taken along a cutting plane line S2-S2 that is perpendicular tothe axial line L2 illustrated in FIG. 13A and passes through a center Gof the spherical shape 180 b 1.

As illustrated in FIGS. 13A, 13B, 14A, and 14B, the coupling member 180mainly includes three portions.

A first portion of the coupling member 180 is the free end portion 180 athat engages with the main body side driving member 100 and receives therotational force from the main body side driving member 100. The freeend portion 180 a includes two protrusions 180 e and 180 f provided atthe distal end portion thereof, along a circle having a centerpositioned on the rotation axis L2 of the coupling member 180. Theprotrusions 180 e and 180 f are disposed point-symmetrically about apoint R where the axial line L2 intersects with a flat surface S17 thatincludes the flat surface portion 180 a 1. When the main body sidedriving member 100 is rotating, the rotational force receiving portions180 e 1 and 180 f 1 provided on the upstream side of the protrusions 180e and 180 f in the rotation direction contact the rotational forceapplying portions 100 a 1 and 100 a 2 of the main body side drivingmember 100. Therefore, the rotational force can be transmitted in therotational direction X6.

A second portion of the coupling member 180 is the connected portion 180b that has a substantially spherical shape. The connected portion 180 bis connected (linked) to the drive input gear 27, which is a rotationalforce transmitted member (i.e., the transmitted member).

A third portion of the coupling member 180 is the linking portion 180 cthat connects the free end portion 180 a to the connected portion 180 b.

The connected portion 180 b will be described in detail below withreference to the attached drawings.

As illustrated in FIGS. 13A, 13B, 14A, and 14B, the connected portion180 b is constituted by the spherical shape 180 b 1 having the center G(i.e., the inclination center) substantially positioned on the axialline L2, the recessed portions 180 b 2 and 180 b 3, and the inclinationregulating portion 180 b 4.

In the present exemplary embodiment, a maximum rotation diameter φZ1 ofthe connected portion 180 b is set to be greater than a maximum rotationdiameter φZ2 of the free end portion 180 a. Further, a diameter φZ3 ofthe linking portion 180 c, which connects the connected portion 180 b tothe free end portion 180 a, is smaller than the maximum rotationdiameters φZ1 and φZ2.

When the coupling member 180 is seen from the rotation axis direction ofthe coupling member 180 (namely, when the coupling member 180 is seenfrom the left side along the direction of arrow V2 in FIG. 13), theouter shape of the free end portion 180 a is greater than the outershape of the linking portion 180 c (i.e., φZ2>φZ3). On the other hand,the outer shape of the connected portion 180 b is greater than the outershape of the free end portion 180 a (i.e., φZ2<φZ1).

The recessed portions 180 b 2 and 180 b 3 include driving forcetransmission surfaces 180 b 6 and 180 b 5 that are in contact with theprotruded portions 27 b 2 and 27 b 3 (see FIG. 1) provided on the driveinput gear 27 and transmit the driving force. Further, the recessedportions 180 b 2 and 180 b 3 include reverse rotation regulatingsurfaces 180 b 8 and 180 b 7 that can regulate a rotation amount in adirection opposite to the driving force transmission direction (seeFIGS. 1A, 1B, and 1C and FIG. 16). Further, as illustrated in FIG. 15,the recessed portions 180 b 2 and 180 b 3 include noncontact sidesurfaces 180 b 9, 180 b 10, 180 b 11, and 180 b 12 and noncontact bottomsurfaces 180 b 13 and 180 b 14. Further, as illustrated in FIGS. 14A,14B, and 15, the recessed portions 180 b 2 and 180 b 3 include protrudedportion confronting surfaces 180 b 15 and 180 b 16. As illustrated inFIGS. 13A, 13B, 14A, and 14B, the inclination regulating portion 180 b 4has a cylindrical shape and is positioned at a side opposite to the freeend portion 180 a of the spherical shape 180 b 1. The inclinationregulating portion 180 b 4 is coaxial with the axial line L2.

The noncontact side surfaces 180 b 9, 180 b 10, 180 b 11, and 180 b 12are parallel to flat surfaces S19 and S20 that pass through the center Gand incline from the axial line L2 by an angle Θ1, as illustrated inFIG. 15. Further, the noncontact side surfaces 180 b 9, 180 b 10, 180 b11, and 180 b 12 are spaced from the flat surfaces S19 and S20 by thesame distance (Z9). Further, as illustrated in FIG. 15, the noncontactbottom surfaces 180 b 13 and 180 b 14 are parallel to a flat surface S21that includes the axial line L2 and passes through the center G. Thenoncontact bottom surfaces 180 b 13 and 180 b 14 are spaced from theflat surface S21 by the same distance (Z17). Further, as illustrated inFIG. 15, the protruded portion confronting surfaces 180 b 15 and 180 b16 are parallel to the flat surface S21 and spaced from the flat surfaceS21 by the same distance (Z10).

Further, as illustrated in FIG. 16, the driving force transmissionsurfaces 180 b 6 and 180 b 5 are parallel to a flat surface S22, whichpasses through the center G of the spherical shape 180 b 1 and includesthe axial line L2, and are spaced from the flat surface S22 by the samedistance (Z8). Further, the reverse rotation regulating surfaces 180 b 8and 180 b 7 according to the present exemplary embodiment are parallelto a flat surface S23, which inclines from the flat surface S22 by anangle Θ2, around the rotation axis L2, and are spaced from the flatsurface S23 by the same distance (Z18).

The coupling member 180 according to the present exemplary embodiment ismade of polyacetal, polycarbonate, PPS, or liquid crystal polymer resin.To improve the rigidity of the coupling member 180, it is useful to addglass fibers or carbon fibers to the above-mentioned resin consideringthe load torque. When the above-mentioned material is contained, therigidity of the coupling member 180 can be improved appropriately.Further, the resin can contain metal inserts to improve the rigidity. Itis also useful to manufacture the coupling member 180 as a metal member.

Further, the free end portion 180 a, the connected portion 180 b, andthe linking portion 180 c can be integrally formed. Alternatively, thesemembers can be formed separately and integrally connected later.

(Relationship between Coupling Member 180 and Drive Input Gear 27)

A relationship between the coupling member 180 and the drive input gear27 will be described in detail below with reference to the attacheddrawings.

FIGS. 17A and 17B are perspective views respectively illustrating thedrive input gear 27. FIG. 17A illustrates the drive input gear 27 seenfrom a viewpoint positioned adjacent to the driving side end face 27 a.FIG. 17B illustrates the drive input gear 27 seen from a viewpointpositioned adjacent to another end surface that is opposite to thedriving side end face 27 a. FIG. 18 illustrates the drive input gear 27seen from a direction indicated by an arrow V1 in FIG. 17A. FIG. 19 is across-sectional view illustrating the drive input gear 27, which istaken along a cutting plane line S3-S3. The cutting plane line S3-S3 isperpendicular to the projected shape of a driving force receivingsurface 27 b 4 illustrated in FIG. 18. FIGS. 20A and 20B illustrate thecoupling member 180 and the drive input gear 27, which are spaced awayfrom each other along the axial lines L2 and L3, in a state where theaxial line L2 substantially coincides with the axial line L3. FIG. 20Ais a perspective view and FIG. 20B is a cross-sectional view taken alonga flat surface S4 illustrated in FIG. 20A.

The drive input gear 27 will be described in detail below with referenceto FIGS. 17A, 17B, 18, and 19. The drive input gear 27 has a cylindricalshape and includes the gear portion (e.g., a helical gear or a spurgear) 27 c that can transmit a driving force to the developing rollergear 29, and the accommodating portion 27 b provided at an internalportion thereof. The accommodating portion 27 b has an inner space thatcan accommodate the connected portion 180 b of the coupling member 180.The accommodating portion 27 b includes an engaging portion 27 b 1 thatprotrudes from an inner wall thereof and engage with the spherical shape180 b 1 of the coupling member 180. The accommodating portion 27 bfurther includes the protruded portions 27 b 2 and 27 b 3 that protrudefrom the engaging portion 27 b 1. The protruded portions 27 b 2 and 27 b3 include the driving force receiving surfaces 27 b 4 and 27 b 5 thatcan receive the driving force from the driving force transmissionsurfaces 180 b 6 and 180 b 5 of the coupling member 180. The drivingforce receiving surface 27 b 4 (and the driving force receiving surface27 b 5) according to the present exemplary embodiment has a semicircularshape having a center L as illustrated in FIG. 19. Further, asillustrated in FIGS. 17A, 17B, and 18, the projected shapes of thedriving force receiving surfaces 27 b 4 and 27 b 5 are point-symmetricalabout a point J where a flat surface S26 (see FIG. 19) intersects withthe rotation axis L3, when seen from the direction V1. The flat surfaceS26 is perpendicular to the rotation axis L3 and passes through thecenter L of the driving force transmission surface 27 b 4. Further, asillustrated in FIG. 18, the projected shapes of the driving forcereceiving surfaces 27 b 4 and 27 b 5 of the drive input gear 27 seenfrom the direction V1 are parallel to each other and spaced from a flatsurface S27 by the same distance (Z5). The flat surface S27 isperpendicular to the flat surface S26 and passes through the point J.Further, as illustrated in FIG. 18, reverse rotation contact surfaces 27b 6 and 27 b 7 provided on the protruded portions 27 b 1 and 27 b 2 areformed point-symmetrically about the point J, flat and parallel to theflat surface S27. The reverse rotation contact surfaces 27 b 6 and 27 b7 are spaced from the flat surface S27 by the same distance (Z4=Z4).

Next, the relationship between the coupling member 180 and the driveinput gear 27 will be described in detail below with reference to theattached drawings. As illustrated in FIGS. 18, 20A, and 20B, the driveinput gear 27 includes recessed portion confronting surfaces 27 b 9 and27 b 10. The recessed portion confronting surfaces 27 b 9 and 27 b 10are flat surfaces parallel to a flat surface S28 that is perpendicularto the flat surface S27 and passes through the point J. The recessedportion confronting surfaces 27 b 9 and 27 b 10 are spaced from the flatsurface S28 by the same distance (Z11). As illustrated in FIGS. 20A and20B, the connected portion 180 b of the coupling member 180 can beassembled with the accommodating portion 27 b of the drive input gear27, while keeping a positional relationship that the protruded portionconfronting surfaces 180 b 15 and 180 b 16 are opposed to and parallelto the recessed portion confronting surfaces 27 b 9 and 27 b 10. In theabove-mentioned configuration, in consideration of the easiness ofassembling, the clearance (Z10+Z10=Z21) between the protruded portionconfronting surfaces 180 b 15 and 180 b 16 is set to be smaller than theclearance (Z11+Z11=Z20) between the recessed portion confrontingsurfaces 27 b 9 and 27 b 10, as illustrated in FIG. 20B.

Hereinafter, another configuration of the coupling member 182 that isemployable in a case where the clearance Z21 between the protrudedportion confronting surfaces 180 b 15 and 180 b 16 is greater than theclearance Z20 between the recessed portion confronting surfaces 27 b 9and 27 b 10 will be described in detail below.

FIGS. 21A1 to 21A4 and FIGS. 21B1 to 21B4 illustrate a method forassembling the coupling member 182 with the drive input gear 27. FIGS.21A1 to 21A4 are side views illustrating the coupling member 182 and thedrive input gear 27. FIG. 21B1 is a cross-sectional view taken along acutting plane line S29-S29 including the axial line L3 illustrated inFIG. 21A1. FIG. 21B2 is a cross-sectional view taken along a cuttingplane line S30-S30 including the axial line L3 illustrated in FIG. 21A2.FIG. 21B3 is a cross-sectional view taken along a cutting plane lineS31-S31 including the axial line L3 illustrated in FIG. 21A3. FIG. 21B4is a cross-sectional view taken along a cutting plane line S32-S32including the rotation axis L13 of the coupling member 182 and the axialline L3 illustrated in FIG. 21A4. The operation for assembling thecoupling member 182 with the drive input gear 27 progresses in the orderfrom FIG. 21A1 to FIG. 21A4.

In an initial stage of the assembling, the coupling member 182 and thedrive input gear 27 are held in a positional relationship that theprotruded portion confronting surfaces 182 b 15 and 182 b 16 confrontthe recessed portion confronting surfaces 27 b 9 and 27 b 10, asillustrated in FIGS. 21A1 and 21B1. The assembling of the couplingmember 180 starts in a state where the axial line L2 inclines from theaxial line L3 by an angle Θ6.

As illustrated in FIG. 21, the coupling member 182 is similar to theabove-mentioned coupling member 180, except the recessed portionconfronting surfaces 182 b 15 and 182 b 16. The recessed portionconfronting surfaces 182 b 15 and 182 b 16 are flat surfaces parallel tothe flat surface S21 that is parallel to the rotation axis L13 of thecoupling member 182 and passes through the center G of the sphericalshape 182 b 1, as illustrated in FIG. 21B4. The recessed portionconfronting surfaces 182 b 15 and 182 b 16 are spaced from the flatsurface S21 by the same distance (Z18). In the above-mentionedconfiguration, as illustrated in FIG. 21B4, the clearance (Z18+Z18=Z22)between the protruded portion confronting surfaces 182 b 15 and 182 b 16is set to be greater than the clearance Z20 between the recessed portionconfronting surfaces 27 b 9 and 27 b 10.

The method for assembling the coupling member 182 with the drive inputgear 27 includes a preparatory step of holding a positional relationshipthat the protruded portion confronting surfaces 182 b 15 and 182 b 16are parallel to and opposed to the recessed portion confronting surfaces27 b 9 and 27 b 10, as illustrated in FIG. 21B1. Further, the assemblingmethod includes a step of inclining the coupling member 182 from therotation axis L3 of the drive input gear 27 by the angle Θ6. In thisstate, by causing the coupling member 182 to move in a directionindicated by an arrow X9 as illustrated in FIG. 21B2, the protrudedportion confronting surface 182 b 15 can pass through the recessedportion confronting surface 27 b 9 of the drive input gear 27. Theassembling method further includes a step of causing the coupling member182 to move in a direction indicated by an arrow X10, which is parallelto a noncontact side surface 182 b 10, as illustrated in FIG. 21B3.Through the above-mentioned operation, the protruded portion confrontingsurface 180 b 16 can approach the axial line L3 closely rather than therecessed portion confronting surface 27 b 10. Therefore, the protrudedportion confronting surface 180 b 16 can directly pass through therecessed portion confronting surface 27 b 10. The assembling methodincludes a final step of causing the coupling member 182 to enter theaccommodating portion 27 b of the drive input gear 27 in the directionX9, while holding a positional relationship that the rotation axis L13of the coupling member 182 nearly coincides with the rotation axis L3 ofthe drive input gear 27, as illustrated in FIG. 21B4. Thus, the couplingmember 182 and the drive input gear 27 can be connected to each other.

The above-mentioned configuration enables the protruded portions 27 b 2and 27 b 3 of the drive input gear 27 to enter and engage with therecessed portions 180 b 2 and 180 b 3 of the coupling member 180, asillustrated in FIGS. 1A to 1C. As a result, the coupling member 180 andthe drive input gear 27 can be integrated together.

Next, a method for assembling the drive input gear 27, which isconnected to the coupling member 180, with the developing cartridge B1will be described in detail below with reference to the attacheddrawings. FIG. 22 is a perspective view illustrating the driving side ofthe developing cartridge B1. FIG. 23 is a cross-sectional view takenalong a flat surface S5 that includes the rotation axis L3 of the driveinput gear 27 illustrated in FIG. 22. FIG. 24 a perspective viewillustrating the developing cartridge B1, in which the coupling member180, the drive input gear 27, and the developing side cover 34 arespaced away from each other in a direction parallel to the rotation axisL3 of the drive input gear 27.

As illustrated in FIGS. 23 and 24, the drive input gear 27 is assembledwith a cylindrical boss 36 b provided on the driving side developingbearing 36. The drive input gear 27 can be rotatably assembled with thedeveloping cartridge B1, by causing a sliding portion 27 b 8 provided onthe accommodating portion 27 b to engage with the gear support surface36 b 1. In this case, as illustrated in FIGS. 23 and 24, the couplingmember 180 is assembled in such a manner that the inclination regulatingportion 180 b 4 is accommodated in the regulating accommodating portion36 a provided on the driving side developing bearing 36.

The developing side cover 34, which prevents the coupling member 180 andthe drive input gear 27 from falling off, has the hole 34 a provided tobare the free end portion 180 a of the coupling member 180. A diameterφZ19 of the hole 34 a is set to be greater than the maximum rotationdiameter φZ2 of the free end portion 180 a of the coupling member 180and smaller than the maximum rotation diameter φZ1 of the connectedportion 180 b.

More specifically, it is now assumed that the coupling member 180 andthe developing side cover 34 are seen from the rotation axis direction(i.e., the direction parallel to the rotation axes of the couplingmember 180 and the drive input gear 27) (namely, seen along the rotationaxis from the left side in FIG. 23). In this case, the outer shape ofthe connected portion 180 b is greater than the outer shape of the freeend portion 180 a (i.e., φZ1>φZ2).

Further, the developing side cover 34 includes the hole (i.e., aperture)34 a that bares the coupling member 180. When the hole 34 a is seen fromthe rotation axis direction, the outer shape of the hole 34 a is greaterthan the outer shape of the free end portion 180 a and is smaller thanthe outer shape of the connected portion (i.e., φZ2<φZ19<φZ1).

Next, another developing side cover that is comparable to theabove-mentioned developing side cover 34 and brings similar effects willbe described in detail below with reference to the attached drawings.FIG. 25 is a perspective view illustrating a developing side cover 35 ina state where the developing side cover 35 is not yet assembled with thedeveloping cartridge B1. FIG. 26 is a perspective view illustrating thedeveloping cartridge B1 that includes the developing side cover 35.

As illustrated in FIGS. 25 and 26, the developing side cover 35 mayinclude a partly opened portion 35 a 1 and a hole (i.e., an aperture) 35a 2 to obtain similar effects. The hole 35 a 2 bares the free endportion 180 a when the developing side cover 35 is assembled with thedriving side developing bearing 36.

The size of the hole 35 a 2 is set to be smaller than the diameter ofthe spherical shape 180 b 1 (i.e., the connected portion 180 b) of thecoupling member 180 to prevent the coupling member 180 from movingtoward the driving side.

More specifically, when the coupling member 180 is forced to moveoutward along the longitudinal direction of the developing roller(toward the free end side of the coupling member 180), the sphericalshape 180 b 1 (the connected portion 180 b) interferes (contacts) withthe developing side cover 35 (i.e., the cover member). Therefore, thecoupling member 180 can be prevented from moving outward. In thisrespect, the developing side cover 35 is a regulating member (a secondregulating member) that prevents the coupling member 180 from movingtoward the free end portion 180 a.

Next, a dimension Z12 of the partly opened portion 35 a 1 is set to begreater than the outer diameter φZ3 of the linking portion 180 c of thecoupling member 180, as illustrated in FIG. 26. On the other hand, thedimension Z12 of the partly opened portion 35 a 1 is set to be smallerthan the outer diameter (φZ1) of the connected portion 180 b of thecoupling member 180.

More specifically, when the developing side cover 35 is seen from therotation axis direction of the coupling member 180, the outer shape ofthe partly opened portion 35 a 1 is greater than the outer shape of thelinking portion 180 c and is smaller than the outer shape of theconnected portion 180 b.

Thus, as illustrated in FIG. 25, it is feasible to slide the developingside cover 35 in a direction of arrow H so that the partly openedportion 35 a 1 can be coupled with the linking portion 180 c of thecoupling member 180. More specifically, the partly opened portion 35 a 1permits the linking portion 180 c to enter the hole 35 a 2.

Thus, irrespective of the outer shape size of the free end portion 180 aof the coupling member 180, the developing side cover 35 can beassembled with the driving side developing bearing 36 in such a way asto prevent the coupling member 180 from falling off. In this case, toavoid any obstruction in the inclination operation of the couplingmember 180, it is desired that the partly opened portion 35 a 1 of aU-shaped groove 35 a is provided in an inclining direction of thecoupling member 180, namely, in the installation direction X1 of thedeveloping cartridge B1.

In the present exemplary embodiment, the drive input gear 27 is aresin-made component that can be formed by an appropriate injectionmolding method. The material of drive input gear 27 is, for example,polyacetal or polycarbonate. Alternatively, it may be useful that thedrive input gear 27 is a metal-made component if a significant loadtorque is required to rotate the photosensitive drum 10.

A practical method for supporting respective constituent components willbe described in detail below with reference to FIGS. 1A to 1C and FIG.23.

The positioning of the coupling member 180 in the direction parallel tothe rotation axis L3 of the drive input gear 27 is determined in such amanner that the coupling member 180 is sandwiched between a sphericalreceiving portion 36 c provided on the driving side developing bearing36 and the spherical retainer portion 34 b provided adjacent to the hole34 a of the developing side cover 34. Further, the positioning of thecoupling member 180 in a direction perpendicular to the axial line L3completes when the spherical shape 180 b 1 is rotatably engaged with theengaging portion 27 b 1 of the drive input gear 27. The positioning ofthe drive input gear 27 in a direction parallel to the axial line L3completes when a gear sliding surface 36 d of the driving sidedeveloping bearing 36 collides with a bearing end surface 27 b 11 of thedrive input gear 27 and a gear retainer surface 34 c of the developingside cover 34 collides with the driving side end face 27 a of the driveinput gear 27. The positioning of the drive input gear 27 in a directionperpendicular to the axial line L3 completes when the sliding portion 27b 8 is rotatably engaged with the gear support surface 36 b 1 providedon the driving side developing bearing 36.

As illustrated in FIG. 1B, when the coupling member 180 rotates in arotational direction X11 around the axial line L2, the driving forcetransmission surfaces 180 b 6 and 180 b 5 provided on the recessedportions 180 b 2 and 180 b 3 are brought into contact with the drivingforce receiving surfaces 27 b 4 and 27 b 5 of the protruded portions 27b 2 and 27 b 3. Therefore, the movement of the coupling member 180 canbe regulated. Alternatively, the movement of the coupling member 180 canbe regulated when the reverse rotation regulating surfaces 180 b 7 and180 b 8 of the recessed portions 180 b 2 and 180 b 3 are brought intocontact with the reverse rotation regulating surfaces 27 b 7 and 27 b 6of the protruded portions 27 b 3 and 27 b 2. Therefore, the position ofthe coupling member 180 can be regulated within a predetermined range inthe rotational direction X11 of the coupling member 180.

Further, in the driving posture state illustrated in FIGS. 1A and 1C,the rotation axis L2 of the coupling member 180 substantially coincideswith the rotation axis L3 of the drive input gear 27. In this state, thenoncontact side surfaces 180 b 9, 180 b 10, 180 b 11 and 180 b 12 andthe noncontact bottom surfaces 180 b 13 and 180 b 14 do not contact withthe protruded portions 27 b 2 and 27 b 3.

As mentioned above, the coupling member 180 can be assembled with thedeveloping cartridge B1 so that the coupling member 180 can inclinerelative to the developing cartridge B1.

Further, as mentioned above, the accommodating portion 27 b, thespherical retainer surface 34 b, and the spherical receiving portion 36c cooperatively regulate the position of the connected portion 180 b.Further, the position of the coupling member 180 can be regulatedsimilarly even when the coupling member 180 is in the inclined state.Accordingly, when the coupling member 180 is inclined (tilted), theintersection of the axial line L2 and the axial line L3 substantiallycoincides with the center G. In other words, the center G is aninclination (tilt) center of the coupling member 180.

(Inclining (Tilting) Operation of Coupling Member 180)

An inclination (tilt) operation of the coupling member 180 will bedescribed in detail below with reference to the attached drawings.

FIGS. 27A and 27B illustrate the developing cartridge B1 in a statewhere the coupling member 180 is inclined. FIG. 27A illustrates thedriving side of the developing cartridge B1. FIG. 27B is across-sectional view taken along a flat surface S9, which includes therotation axis L2 of the coupling member 180, illustrated in FIG. 27A.

As illustrated in FIGS. 27A and 27B, the coupling member 180 inclinesaround the center G by the function of the coupling spring 185. Theinclination regulating portion 180 b 4 contacts a regulating portion 36a 1 of the driving side developing bearing 36. Therefore, the couplingmember 180 is in an inclined posture with an inclination angle Θ8. Inthis case, the noncontact side surfaces 180 b 9 and 180 b 12 of thecoupling member 180 do not contact the protruded portions 27 b 3 and 27b 2 of the drive input gear 27. Further, the recessed portions 180 b 2and 180 b 3 of the coupling member 180 and the protruded portions 27 b 2and 27 b 3 of the drive input gear 27 are constituted to hold theinclined posture relative to the inclination direction, by causing theinclination regulating portion 180 b 4 to contact the regulating portion36 a 1 in any phase in the axial line L2 rotational direction.

Similarly, the noncontact side surfaces 180 b 10 and 180 b 11 of thecoupling member 180 do not contact the protruded portions 27 b 3 and 27b 2 of the drive input gear 27 when the coupling member 180 is in theinclined posture. No problem will occur even when the noncontact sidesurfaces 180 b 9, 180 b 10, 180 b 11, and 180 b 12 and the noncontactbottom surfaces 180 b 13 and 180 b 14 are modified from the shapesdescribed in the present exemplary embodiment (see FIGS. 1A to 1C andFIGS. 27A and 27B). More specifically, it is essentially required thatthe noncontact side surfaces 180 b 9, 180 b 10, 180 b 11, and 180 b 12and the noncontact bottom surfaces 180 b 13 and 180 b 14 do not contactthe protruded portions 27 b 1 and 27 b 2 of the coupling member 180 inthe driving posture and the inclined posture.

As mentioned above, the coupling member 180 can incline (tilt) from therotation axis L3 of the driving force transmission member 27 with thepredetermined inclination angle Θ8 in substantially all directions. Morespecifically, the coupling member 180 can incline (tilt) relative to theaxial line L3 in any direction. Further, the coupling member 180 canswing relative to the axial line L3 in any direction. Further, thecoupling member 180 can turn around the axial line L3 substantially inall directions. In the present exemplary embodiment, the turning of thecoupling member 180 can be defined as a rotational motion of theinclined (tilted) axial line L2 around the axial line L3.

Another configuration capable of preventing the coupling member 182 fromfalling off, which is applicable in a case where the above-mentionedcoupling member 182 is used, will be described in detail below.

FIGS. 28A and 28B are cross-sectional views illustrating the couplingmember 182, the drive input gear 27, and a developing side cover 45,which are assembled with a driving side developing bearing 38. FIG. 28Aillustrates the coupling member 182 in the driving posture. FIG. 28Billustrates the coupling member 182 in the inclined posture, in whichthe coupling member 182 has been moved toward the driving side. Asillustrated in FIG. 28B, a regulating portion 38 a 1 of the driving sidedeveloping bearing 38 is brought into contact with the inclinationregulating portion 182 b 4 if the coupling member 182 is tilted. As aresult, a rotation axis L15 of the coupling member 182 inclines from theaxial line L3 by an angle Θ7. The angle Θ7 is set to be smaller than theangle Θ6 (Θ7<Θ6). The angle Θ6 is the angle having been described in theprocess of inserting the coupling member 182 in the drive input gear 27with reference to FIG. 21. Thus, as illustrated in FIG. 28B, theprotruded portion 27 b 2 of the drive input gear 27 collides with thecoupling member 182 b 12. The coupling member 182 can be prevented frombeing disengaged from the developing input gear 27 in a direction X13.Thus, the size of a hole 45 a that bares a free end portion 182 a of thecoupling member 182 provided on the developing side cover 45 can be setadequately irrespective of the outer diameter of the spherical shape 182b 1 of the coupling member 182.

Further, a developing cartridge B2 including a coupling member 183 thatcan incline according to another method will be described in detailbelow.

FIGS. 29A and 29B are perspective views illustrating the developingcartridge B2, which is seen from a driving side thereof. FIG. 29Aillustrates the coupling member 183 in the driving posture, and FIG. 29Billustrates the coupling member 183 in the inclined posture. FIGS. 30Aand 30B illustrate another configuration of the developing cartridge B2,in which the coupling member 183 is in the inclined posture. FIG. 30A isa side view illustrating the developing cartridge B2. FIG. 30B is across-sectional view taken along a flat surface S36 illustrated in FIG.30A. The flat surface S36 includes a rotation axis L16 of the couplingmember 183.

As illustrated in FIG. 30B, the coupling member 183 has a connectedportion 183 b that does not include a portion comparable to theinclination regulating portion 180 b 4 illustrated in FIGS. 13A and 13B.The coupling member 183 has a configuration similar to that of theabove-mentioned coupling member 180 illustrated in FIGS. 13A and 13B,except for the shape of the inclination regulating portion 180 b 4.

As illustrated in FIG. 29A, a developing side cover 55 of the developingcartridge B2 includes a through-hole 55 a through which a free endportion 183 a of the coupling member 183 can move smoothly. Similar tothe above-mentioned hole 34 a of the developing side cover 34illustrated in FIG. 23, the hole 55 a is constituted in such a way as toprevent the coupling member 183 from falling off. The hole 55 a includesan inclination regulating portion 55 a 1 that can be brought intocontact with a linking portion 183 c of the coupling member 183. Inother words, the inclination regulating portion 55 a 1 can regulate theinclination amount of the coupling member 183 in an inclinationdirection X11. As illustrated in FIGS. 30A and 30B, the coupling spring185 causes the coupling member 183 to incline about a center G1 of aspherical shape 183 b 1 so that the linking portion 183 c contacts theinclination regulating portion 55 a 1. Thus, the coupling member 183takes the inclined posture. It has been described with reference toFIGS. 27A and 27B that the noncontact surfaces 180 b 9, 180 b 10, 180 b11, and 180 b 12 of the coupling member 180 do not contact the protrudedportions 27 b 3 and 27 b 2 of the drive input gear 27. The configurationof the present exemplary embodiment illustrated in FIGS. 30A and 30B ischaracterized in that noncontact surfaces do not contact protrudedportions. In this respect, the configuration of the present exemplaryembodiment is similar to the above-mentioned configuration including thecoupling member 180 and the drive input gear 27. Therefore, redundantdescription thereof will be avoided.

As mentioned above, the coupling member 183 can incline (tilt) from therotation axis L3 of the driving force transmission member 27 with apredetermined inclination angle in substantially all directions. Morespecifically, the coupling member 183 can incline (tilt) relative to theaxial line L3 in any direction. Further, the coupling member 183 canswing relative to the axial line L3 in any direction. Further, thecoupling member 183 can turn around the axial line L3 in substantiallyall directions. In the present exemplary embodiment, the turning of thecoupling member 183 can be defined as a rotational motion of theinclined (tilted) axial line L16 around the axial line L3.

The above-mentioned configuration can be summarized in the followingmanner.

The cartridge (i.e., the developing cartridge B1) according to thepresent exemplary embodiment is attachable to and detachable from theapparatus body that includes the rotatable main body side driving member100 (see FIG. 12).

The developing cartridge B1 is movable in a predetermined directionsubstantially perpendicular to the rotation axis of the main body sidedriving member 100 so that the developing cartridge B1 can be attachedto and detached from the apparatus body. More specifically, thedeveloping cartridge B1 can be attached to and detached from theapparatus body by moving in the right-and-left direction in FIG. 12B1 to12B4.

The developing cartridge B1 includes the developing roller 13 (i.e., thedeveloper carrier) as the rotary member that rotates in a state wherethe developer adheres to the surface thereof (see FIG. 3).

Further, the developing cartridge B1 includes the coupling member 180that engages with the main body side driving member 100 and thetransmitted member (i.e., the drive input gear 27) that can receive arotational force from the coupling member 180.

The drive input gear 27 includes the accommodating portion 27 bconfigured to accommodate the coupling member 180 and the gear portion27 c configured to transmit the driving force received from the couplingmember 180 to the outside of the drive input gear 27 (see FIGS. 17A and17B). More specifically, the drive input gear 27 is a member thattransmits the rotational force (i.e., the driving force) to thedeveloping roller 13 by causing the gear portion 27 c to engage with thedeveloping roller gear 29 (see FIG. 6).

Further, the drive input gear 27 includes the protruded portions 27 b 2and 27 b 3 integrally formed with the inner wall of the accommodatingportion 27 b. These protruded portions 27 b 2 and 27 b 3 are portionsextending (protruding) from the inner wall of the accommodating portion27 b toward the inner space of the accommodating portion 27 b.

Respective portions (i.e., the accommodating portion 27 b, the gearportion 27 c, and the protruded portions 27 b 2 and 27 b 3) of the driveinput gear 27 are integrally formed.

As illustrated in FIGS. 13A and 13B, the coupling member 180 includesthe free end portion 180 a, the connected portion 180 b, and the linkingportion 180 c. The free end portion 180 a is a portion that contacts themain body side driving member 100. The rotational force receivingportions 180 e 1 and 180 f 1 are provided on the free end portion 180 ato receive the rotational force from the main body side driving member100. The connected portion 180 b is a portion that can be accommodatedin the accommodating portion 27 b provided in the rotational forcetransmitted member (i.e., the driving force input gear 27), asillustrated in FIG. 21B4 and FIG. 23). The connected portion 180 bincludes the recessed portions 180 b 2 and 180 b 3 formed thereon. Theprotruded portions 27 b 2 and 27 b 3 of the drive input gear 27 canenter the recessed portions 180 b 2 and 180 b 3. The linking portion 180c is a portion that connects the free end portion 180 a to the connectedportion 180 b.

The coupling member 180 is movable relative to the drive input gear 27.More specifically, the coupling member 180 can incline around theconnected portion 180 b that serves as a fulcrum. The coupling member180 can engage with or disengage from the main body side driving member100 by changing the inclination angle thereof.

As understood from FIGS. 12B1 to 12B4, the gradient (inclination angle)of the axial line L2 of the coupling member 180 relative to the axialline L3 of the drive input gear 27 or the axial line L1 of the main bodyside driving member 100 changes before and after the coupling member 180is engaged with the main body side driving member 100.

For example, when the developing cartridge B1 is taken out of theapparatus body, the state of the coupling member 180 changes in theorder of FIGS. 12B4, 12B3, 12B2, and 12B1. More specifically, thecoupling member 180 moves away from the drive input gear 27 in such amanner that the rotation center (the axial line L1) of the main bodyside driving member and the rotation center (the axial line L3) of thetransmitted member (i.e., the drive input gear 27) depart from eachother in a direction substantially perpendicular to the axial line L1(namely, in the right-and-left direction in FIG. 12B1 to 12B4). Theabove-mentioned movement causes the free end portion 180 a of thecoupling member 180 (i.e., the rotational force receiving portions 180 e1 and 180 f 1) to disengage from the main body side driving member 100.To permit the above-mentioned disengagement, the axial line L2 of thecoupling member 180 inclines from the rotation axis L3 of the driveinput gear 27. More specifically, the inclination angle of the axialline L2 relative to the axial line L3 becomes greater.

Further, the protruded portions 27 b 2 and 27 b 3 of the drive inputgear 27 are engaged with the recessed portions 180 b 2 and 180 b 3 insuch a way as to enable the coupling member 180 to incline. Morespecifically, there is a clearance between the inner wall of therecessed portions 180 b 2 and 180 b 3 and the protruded portions 27 b 2and 27 b 3. Therefore, the recessed portions 180 b 2 and 180 b 3 aremovable relative to the protruded portions 27 b 2 and 27 b 3 (see FIG.21B4).

Further, when the coupling member 180 rotates, the recessed portions 180b 2 and 180 b 3 contact the protruded portions 27 b 2 and 27 b 3.Therefore, the drive input gear 27 can receive the rotational force(i.e., the driving force) from the coupling member 180.

The coupling member 180 that includes the recessed portions 180 b 2 and180 b 3 provided at the connected portion 180 b is caused to beconnected with the drive input gear 27 that includes the protrudedportions 27 b 2 and 27 b 3 provided at the accommodating portion 27 b inthe accommodating portion 27 b and the connected portion 180 b.Therefore, it is feasible to connect the coupling member 180 to thedrive input gear 27 so that the coupling member 180 can incline relativeto the drive input gear 27. Thus, it is feasible to provide an easyassembling method capable of connecting the coupling member 180 with thedrive input gear 27 without requiring any specific component. In thepresent exemplary embodiment, an assembly of the coupling member 180 andthe drive input gear 27 can be regarded as an integrally rotatablerotary unit.

Next, a second exemplary embodiment of the present invention, which ischaracterized in that the rotational force is transmitted from theapparatus body A1 side of the drum cartridge C, will be described indetail below. A configuration according to the second exemplaryembodiment includes the coupling member 183 described in the firstexemplary embodiment. Further, the configuration according to the secondexemplary embodiment is similar to that configuration described in thefirst exemplary embodiment, except for a driving side flange 37 servingas a rotational force transmitted member (i.e., a transmitted member)and a configuration of a drum cartridge C1. Therefore, the samecomponents are denoted by the same reference numerals and redundantdescription thereof will be avoided.

(Configuration of Coupling Member 183 and Driving Side Flange 37)

A practical relationship between the coupling member 183 and the drivingside flange 37 will be described in detail below with reference to theattached drawings.

FIGS. 31A and 31B are exploded perspective views illustrating a drivingforce transmission unit U2. FIG. 31A illustrates the driving forcetransmission unit U2 seen from a driving side thereof. FIG. 31Billustrates the driving force transmission unit U2 seen from anon-driving side thereof. FIGS. 32 and 33 illustrate a practicalconfiguration of the coupling member 183 and the driving side flange 37.FIG. 32 is a perspective view illustrating the drum cartridge C1 seenfrom a driving side thereof. FIG. 33 is a cross-sectional viewillustrating the coupling member 183 and the driving side flange 37,taken along a flat surface S13 passing through a rotation axis L14 ofthe coupling member 183 and a rotation axis L10 of the photosensitivedrum 10 illustrated in FIG. 32. FIG. 34A is a perspective viewillustrating the driving side of the drum cartridge C1. FIG. 34B is aside view illustrating the driving side of the drum cartridge C1.

As illustrated in FIGS. 31A and 31B, the driving side flange unit U2includes the coupling member 183, the driving side flange 37, and aregulating member (i.e., a first regulating member) 89. Theconfiguration capable of transmitting the driving force from thecoupling member 180 to the developing input gear 27 has been describedwith reference to FIGS. 1A to 1C in the first exemplary embodiment. Aconfiguration for transmitting the driving force from the couplingmember 183 to the drum flange 37 according to the present exemplaryembodiment illustrated in FIGS. 31A and 31B is similar to theabove-mentioned configuration for transmitting the driving force fromthe coupling member 180 to the drive input gear 27. Therefore, redundantdescription thereof will be avoided. According to the above-mentionedconfiguration, the driving force can be transmitted from the drivingside flange 37 to the photosensitive drum 10.

The regulating member 89 can enter an accommodating portion 37 a from aninner side of the developing roller 13 in the longitudinal direction(i.e., from the left side in FIG. 31B). The regulating member 89collides with the connected portion 183 b to regulate the movement ofthe coupling member 183 in such a way as to prevent the coupling member183 from separating from the driving side flange 37 in a direction X12illustrated in FIGS. 31A and 31B (see FIGS. 31A, 31B, and 33). Morespecifically, by colliding with the connected portion 183 b, theregulating member 89 prevents the coupling member 183 from moving towardthe connected portion side (i.e., the inner side in the longitudinaldirection of the photosensitive drum 10 or the developing roller 13).

The driving side flange 37 includes a fixed portion 37 e, a gear portion37 c (e.g., a helical gear or a spur gear), and a supported portion 37d. The fixed portion 37 e is a portion fixed to the photosensitive drum10 (see FIG. 33). Further, the driving side flange 37 has a hollow shapeand includes an accommodating portion 37 b provided therein. Theaccommodating portion 37 b has an internal portion that can accommodatethe connected portion 183 b of the coupling member 183. The connectedportion 183 b of the coupling member 183 can enter a flange hole 37 mprovided on the driving side of the driving side flange 37 (see FIG. 31Aand FIG. 33). The supported portion 37 d is supported by a flangesupport portion 30 a of the drum bearing 30 (see FIGS. 31A, 31B, and33). The drum bearing 30 includes a coupling hole 30 b through which thefree end portion 183 a of the coupling member 183 can move smoothly (seeFIGS. 32 and 33).

Similar to the hole 34 a of the developing side cover 34 according tothe first exemplary embodiment illustrated in FIG. 23, the coupling hole30 b can prevent the coupling member 183 from falling off.

The configuration of the inclination regulating portion 55 a 1 of thedeveloping side cover 55 has been described with reference to FIGS. 30Aand 30B in the first exemplary embodiment. As illustrated in FIG. 33,the drum bearing 30 according to the present exemplary embodimentincludes an inclination regulating portion 30 b 1, which is similar tothe above-mentioned inclination regulating portion 55 a 1. Therefore,redundant description thereof will be avoided. The engaging portion 27 b1 of the drive input gear 27 has been described with reference to FIG.23 in the first exemplary embodiment. As illustrated in FIG. 33, thedriving side flange 37 according to the present exemplary embodimentincludes an engaging portion having a configuration similar to that ofthe above-mentioned engaging portion 27 b 1. Therefore, redundantdescription thereof will be avoided.

The configuration of the protruded portions 27 b 2 and 27 b 3 of thedrive input gear 27 has been described with reference to FIGS. 1A to 1Cin the first exemplary embodiment. As illustrated in FIG. 33, thedriving side flange 37 according to the present exemplary embodimentincludes protruded portions 37 b 2 and 37 b 3, which are similar to theabove-mentioned protruded portions 27 b 2 and 27 b 3. Therefore,redundant description thereof will be avoided.

The configuration capable of transmitting the driving force from thedriving force transmission surfaces 180 b 5 and 180 b 6 of the couplingmember 180 to the driving force receiving surfaces 27 b 4 and 27 b 5 ofthe drive input gear 27 has been described with reference to FIGS. 1A to1C in the first exemplary embodiment. As illustrated in FIG. 33, thecoupling member 183 and the driving side flange 37 according to thepresent exemplary embodiment are configured to transmit the drivingforce from the driving force transmission surface to the driving forcereceiving surface. Therefore, redundant description thereof will beavoided. The regulating member 89 includes a base portion 89 a having asemi-spherical shape (see FIG. 33).

A method for supporting each constituent component and a method forlinking respective constituent components will be described in detailbelow with reference to FIG. 33.

Similar to the configurations of the recessed portions 180 b 2 and 180 b3 and the protruded portions 27 b 2 and 27 b 3 having been describedwith reference to FIGS. 1A to 1C in the first exemplary embodiment, theprotruded portions 37 b 2 and 37 b 3 of the driving side flange 37 canenter recessed portions 183 b 2 and 183 b 3 of the coupling member 183.A connected portion 181 b is coupled with the accommodating portion 37 bso that the above-mentioned state can be realized. The configurationcapable of regulating the movement in a direction perpendicular to theaxial line L3 by bringing the spherical shape 180 b 1 of the couplingmember 180 into contact with the engaging portion 27 b 1 has beendescribed with reference to FIG. 23 in the first exemplary embodiment.The coupling member 183 according to the present exemplary embodiment isconfigured to regulate the movement in a direction perpendicular to theaxial line L10 of the driving side flange 37 by bringing theabove-mentioned spherical shape into contact with the engaging portion.Therefore, redundant description thereof will be avoided. Further, themovement of the coupling member 183 in the direction X12 can beregulated by bring the spherical shape 183 b 1 into contact with thebase portion 89 a of the regulating member 89. Further, the movement ofthe coupling member 183 in the direction X13 can be regulated bybringing the spherical shape 183 b 1 into contact with a couplingretainer portion 30 b 2 of the drum bearing 30. The configuration thatthe driving force transmission surfaces 180 b 5 and 180 b 6 of thecoupling member 180 and the driving force receiving surfaces 27 b 4 and27 b 5 of the drive input gear 27 cooperatively determine thepositioning in a rotational direction around the axial line L2 has beendescribed with reference to FIGS. 1A to 1C in the first exemplaryembodiment. Similarly, the coupling member 183 according to the presentexemplary embodiment has driving force transmission surfaces that arecooperative with driving force receiving surfaces of the driving sideflange 37 to determine the positioning in a rotational direction aroundan axial line L14. In configuration, the coupling member 183 and thedriving side flange 37 are similar to the above-mentioned combination ofthe coupling member 180 the drive input gear 27. Therefore, redundantdescription thereof will be avoided. The configuration that the reverserotation regulating surfaces 180 b 7 and 180 b 8 of the coupling member180 and the reverse rotation contact surfaces 27 b 6 and 27 b 7 of thedrive input gear 27 cooperatively determine the positioning in adirection opposite to the rotational direction around the rotation axisL2 has been described with reference to FIGS. 1A and 1C in the firstexemplary embodiment. Similarly, the coupling member 183 according tothe present exemplary embodiment has reverse rotation regulatingsurfaces that are cooperative with reverse rotation contact surfaces ofthe driving side flange 37 to determine the positioning in a directionopposite to the rotational direction around the rotation axis L14. Inconfiguration, the coupling member 183 and the driving side flange 37are similar to the above-mentioned combination of the coupling member180 and the drive input gear 27. Therefore, redundant descriptionthereof will be avoided.

As mentioned above, the coupling member 183 can be linked with thedriving side flange 37 so that the coupling member 183 can inclinerelative to the driving side flange 37.

Further, as mentioned above, the accommodating portion 37 b, thecoupling retainer portion 30 b 2, and the base portion 89 acooperatively regulate the position of the coupling member 183 in adirection perpendicular to the axial line L10 of the spherical shape 183b 1 as well as in the directions X12 and X13. Accordingly, when thecoupling member 183 inclines (tilts) about the center G2 of thespherical shape 183 b 1, the intersection of the rotation axis L10 ofthe photosensitive drum and the rotation axis L14 of the coupling member183 substantially coincides with the center G2. In other words, thecenter G2 is an inclination (tilt) center of the coupling member 183.

Further, as illustrated in FIG. 34, a coupling spring 186 is provided onthe drum bearing 30. For example, the coupling spring 186 is a torsioncoil spring. A positioning portion 186 a of the coupling spring 186 issupported by a spring supporting portion 30 h of the drum bearing 30.Further, one end portion 186 b of the coupling spring 186 is fixed to aspring contact portion 30 j of the drum bearing 30. Further, the otherend portion 186 c of the coupling spring 186 is brought into contactwith the linking portion 183 c of the coupling member 183. Therefore, arestorative force of the coupling spring 186 causes the coupling member183 to incline.

(Inclining (Tilting) Operation of Coupling Member 183)

An inclining (tilting) operation of the coupling member 183 will bedescribed in detail below.

According to the configuration according to the first exemplaryembodiment illustrated in FIGS. 30A and 30B, the linking portion 183 cof the coupling member 183 collides with the inclination regulatingportion 55 a 1 of the developing side cover 55 so that the couplingmember 183 can take the inclined posture. Similarly, the linking portion183 c according to the present exemplary embodiment is configured tocollide with the inclination regulating portion 36 b 1 of the drumbearing 30 so that the coupling member 183 can take the inclinedposture. In this case, the axial line L3 illustrated in FIG. 30B iscomparable to the rotation axis L10 of the photosensitive drum 10according to the present exemplary embodiment. As mentioned above, thecoupling member 183 can incline (tilt) from the rotation axis L10 of thephotosensitive drum 10 with a predetermined inclination angle insubstantially all directions. More specifically, the coupling member 183can incline (tilt) with respect to the axial line L10 in any direction.Further, the coupling member 183 can swing relative to the axial lineL10 in any direction. Further, the coupling member 183 can turn aroundthe axial line L10 in substantially all directions. In the presentexemplary embodiment, the turning of the coupling member 183 can bedefined as a rotational motion of the inclined (tilted) axial line L14around the axial line L10.

In the present exemplary embodiment, an assembly of the coupling member183, the driving side flange 37, the regulating member 89, and thephotosensitive drum 10 can be regarded as an integrally rotatable rotaryunit.

According to the configuration described in the second exemplaryembodiment, the driving force is directly transmitted from the couplingmember 183 to the photosensitive drum 10. A similar configuration isapplicable to the developing roller 13 or other rotary members.

The above-mentioned configuration can be summarized in the followingmanner.

The coupling member 183 that includes the recessed portions 183 b 2 and183 b 3 provided at the connected portion 183 b is caused to beconnected with the driving side flange 37 that includes the protrudedportions 37 b 2 and 37 b 3 provided at the accommodating portion 37 b inthe accommodating portion 37 b and the connected portion 181 b.Therefore, it is feasible to connect the coupling member 183 to thedriving side flange 37 so that the coupling member 183 can inclinerelative to the driving side flange 37. Thus, it is feasible to providean easy assembling configuration that does not require any specificcomponent even in a configuration that the rotational force istransmitted to the photosensitive drum 10 from the apparatus body A1side of the drum cartridge C1.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

What is claimed is:
 1. A coupling member for an image forming apparatuscartridge, the coupling member comprising: a first end portion having afirst recess and a second recess formed therein, the first and secondrecesses being positioned on opposite sides of the first end portion,and the first and second recesses being separated from each other by apart of the first end portion, with (i) a first surface, a secondsurface, and a third surface facing the first recess, the first andsecond surfaces being positioned opposite to each other and the thirdsurface being positioned between the first and second surfaces, and (ii)a first surface, a second surface, and a third surface facing the secondrecess, the first and second surfaces being positioned opposite to eachother and the third surface being positioned between the first andsecond surfaces; and a second end portion opposite to the first endportion, the second end portion including at least one projectionconfigured to receive a rotational force.
 2. The coupling memberaccording to claim 1, further comprising a connecting portion thatconnects the first end portion and the second end portion.
 3. Thecoupling member according to claim 2, wherein, as measured along a lineperpendicular to an axis of the coupling member, a distance from theaxis to an outermost surface of the connecting portion is less than adistance from the axis to at least part of an outermost surface of thesecond end portion.
 4. The coupling member according to claim 1, whereinthe second end portion includes two projections that are positioned onopposite sides of the second end portion.
 5. The coupling memberaccording to claim 4, wherein the second end portion includes a surfacewith a recess formed therein, with the two projections projecting fromthe surface.
 6. The coupling member according to claim 1, furthercomprising a projection extending from the first end portion in adirection away from the second end portion.
 7. The coupling memberaccording to claim 1, wherein the third surface facing the first recessand the third surface facing the second recess are parallel to eachother.
 8. The coupling member according to claim 7, wherein the thirdsurface facing the first recess and the third surface facing the secondrecess extend parallel to a rotational axis of the coupling member. 9.The coupling member according to claim 1, wherein the third surfacefacing the first recess and the third surface facing the second recessextend parallel to a rotational axis of the coupling member.
 10. Acoupling member for an image forming apparatus cartridge, the couplingmember comprising: a first end portion including an outer surface, withfirst and second recesses formed in opposite sides of the outer surface,the first and second recesses being separated from each other by a partof the first end portion, wherein a surface of first end portion facingthe first recess extends parallel to a surface of the first end portionthat faces the second recess; and a second end portion opposite to thefirst end portion, the second end portion including at least oneprojection configured to receive a rotational force.
 11. The couplingmember according to claim 10, further comprising a connecting portionthat connects the first end portion and the second end portion.
 12. Thecoupling member according to claim 11, wherein, as measured along a lineperpendicular to an axis of the coupling member, a distance from theaxis to an outermost surface of the connecting portion is less than adistance from the axis to at least part of an outermost surface of thesecond end portion.
 13. The coupling member according to claim 10,wherein the second end portion includes two projections that arepositioned on opposite sides of the second end portion.
 14. The couplingmember according to claim 13, wherein the second end portion includes asurface with a recess formed therein, with the two projectionsprojecting from the surface.
 15. The coupling member according to claim10, further comprising a projection extending from the outer surface ofthe first end portion in a direction away from the second end portion.16. The coupling member according to claim 10, wherein the surface offirst end portion facing the first recess and the surface of first endportion facing the second recess are parallel with each other.
 17. Thecoupling member according to claim 16, wherein the surface of first endportion facing the first recess and the surface of first end portionfacing the second recess extend parallel to a rotational axis of thecoupling member.
 18. The coupling member according to claim 10, whereinthe surface of first end portion facing the first recess and the surfaceof first end portion facing the second recess extend parallel to arotational axis of the coupling member.
 19. A developing cartridgecomprising: a casing; developer contained within the casing; adeveloping roller rotatably supported by the casing, the developingroller being configured to carry the developer on a surface thereof; acoupling member operatively connected to the developing roller such thatthe coupling member is capable of transmitting a rotational force to thedeveloping roller, the coupling member comprising: a first end portionhaving a first recess and a second recess formed therein, the first andsecond recesses being positioned on opposite sides of the first endportion, and the first and second recesses being separated from eachother by a part of the first end portion, with (i) a first surface, asecond surface, and a third surface facing the first recess, the firstand second surfaces being positioned opposite to each other and thethird surface being positioned between the first and second surfaces,and (ii) a first surface, a second surface, and a third surface facingthe second recess, the first and second surfaces being positionedopposite to each other and the third surface being positioned betweenthe first and second surfaces; and a second end portion opposite to thefirst end portion, the second end portion including at least oneprojection configured to receive a rotational force.
 20. The developingcartridge according to claim 19, wherein the coupling member furthercomprises a connecting portion that connects the first end portion andthe second end portion.
 21. The developing cartridge according to claim20, wherein, as measured along a line perpendicular to an axis of thecoupling member, a distance from the axis to an outermost surface of theconnecting portion is less than a distance from the axis to at leastpart of an outermost surface of the second end portion.
 22. Thedeveloping cartridge according to claim 19, wherein the second endportion of the coupling member includes two projections that arepositioned on opposite sides of the second end portion.
 23. Thedeveloping cartridge according to claim 22, wherein the second endportion includes a surface with a recess formed therein, with the twoprojections projecting from the surface.
 24. The developing cartridgeaccording to claim 19, further comprising a projection extending fromthe first end portion in a direction away from the second end portion.25. The developing cartridge according to claim 19, wherein the thirdsurface facing the first recess and the third surface facing the secondrecess are parallel with each other.
 26. The developing cartridgeaccording to claim 25, wherein the third surface facing the first recessand the third surface facing the second recess extend parallel to arotational axis of the coupling member.
 27. The developing cartridgeaccording to claim 19, wherein the third surface facing the first recessand the third surface facing the second recess extend parallel to arotational axis of the coupling member.
 28. A developing cartridgecomprising: a casing; developer contained within the casing; adeveloping roller rotatably supported by the casing, the developingroller being configured to carry the developer on a surface thereof; acoupling member operatively connected to the developing roller such thatthe coupling member is capable of transmitting a rotational force to thedeveloping roller, the coupling member comprising: a first end portionincluding an outer surface, with first and second recesses formed inopposite sides of the outer surface, the first and second recesses beingseparated from each other by a part of the first end portion, wherein asurface of first end portion facing the first recess extends parallel toa surface of the first end portion that faces the second recess; and asecond end portion opposite to the first end portion, the second endportion including at least one projection configured to receive arotational force.
 29. The developing cartridge according to claim 28,wherein the coupling member further comprises a connecting portion thatconnects the first end portion and the second end portion.
 30. Thedeveloping cartridge according to claim 29, wherein, as measured along aline perpendicular to an axis of the coupling member, a distance fromthe axis to an outermost surface of the connecting portion is less thana distance from the axis to at least part of an outermost surface of thesecond end portion.
 31. The developing cartridge according to claim 28,wherein the second end portion of the coupling member includes twoprojections that are positioned on opposite sides of the second endportion.
 32. The developing cartridge according to claim 31, wherein thesecond end portion includes a surface with a recess formed therein, withthe two projections projecting from the surface.
 33. The developingcartridge according to claim 28, further comprising a projectionextending from the outer surface of the first end portion in a directionaway from the second end portion.
 34. The developing cartridge accordingto claim 28, wherein the surface of first end portion facing the firstrecess and the surface of first end portion facing the second recess areparallel with each other.
 35. The developing cartridge according toclaim 34, wherein the surface of first end portion facing the firstrecess and the surface of first end portion facing the second recessextend parallel to a rotational axis of the coupling member.
 36. Thedeveloping cartridge according to claim 28, wherein the surface of firstend portion facing the first recess and the surface of first end portionfacing the second recess extend parallel to a rotational axis of thecoupling member.